Global Patent Index - EP 1062180 A1

EP 1062180 A1 2000-12-27 - METHOD FOR PROCESSING SILICON USING ETCHING PROCESSES

Title (en)

METHOD FOR PROCESSING SILICON USING ETCHING PROCESSES

Title (de)

VERFAHREN ZUR BEARBEITUNG VON SILIZIUM MITTELS ÄTZPROZESSEN

Title (fr)

PROCEDE POUR LE TRAITEMENT DE SILICIUM AU MOYEN DE PROCESSUS DE GRAVURE

Publication

EP 1062180 A1 (DE)

Application

EP 99955752 A

Priority

  • DE 9903018 W
  • DE 19847455 A

Abstract (en)

[origin: DE19847455A1] Silicon multi-layer etching comprises anisotropic plasma etching of trenches (21') down to a buried separation layer (12,14,14',16), etching the exposed separation layer and then etching an underlying silicon layer (17, 17'). Etching of a layered silicon body, having a first silicon layer (15) provided with an etch mask (10), comprises: (a) a first anisotropic plasma etching operation which produces trenches (21') in the region of the mask openings (21) and which terminates at a separation layer (12,14,14',16) buried between the first silicon layer (15) and a further silicon layer (17,17'); (b) a second etching operation for etching through the exposed portions (23,23') of the separation layer; and (c) a third etching operation to etch the further silicon layer (17,17'). Preferred Features: The third etching operation produced complete isotropic under-etching between two or more trenches so that a free standing structure (32) is created. The first etching operation is a dry etching operation comprising alternate deposition and isotropic etching steps, the deposition steps being carried out using a high density plasma (especially a PIE (propagation ion etching) plasma or an ICP (inductively coupled plasma)) of a polymer-forming monomer source gas which forms a Teflon (RTM) like film (20) on the trench side walls, while the etching steps employ a fluorine radical source gas, especially SF6 with added oxygen. The separation layer comprises a first section (12) of silicon dioxide, silicon oxide, silicon nitride, glass and/or ceramic, especially thermally grown silicon dioxide, and a second section (16) of silicon dioxide deposited by CVD especially from silanes. The separation layer sections (12, 16) are 500 nm to 50 mu m (especially 1-10 mu m) thick. The second etching operation is a dry chemical, especially plasma, etching operation or possibly a wet chemical etching operation using dilute hydrofluoric acid. All the etching operations are carried out in a single etching chamber and the etched body is post-treated in an oxygen plasma stripper for ashing of the mask and the residual Teflon (RTM) like film.

IPC 1-7 (main, further and additional classification)

B81B 3/00

IPC 8 full level (invention and additional information)

B81C 1/00 (2006.01); B81B 3/00 (2006.01); H01L 21/302 (2006.01); H01L 21/3065 (2006.01)

CPC (invention and additional information)

H01L 21/30655 (2013.01); B81C 1/00571 (2013.01); B81C 2201/014 (2013.01)

Citation (search report)

See references of WO 0023376A1

Designated contracting state (EPC)

DE FR GB NL

EPO simple patent family

DE 19847455 A1 20000427; EP 1062180 A1 20001227; JP 2002527253 A 20020827; JP 4518453 B2 20100804; US 7052623 B1 20060530; WO 0023376 A1 20000427

INPADOC legal status


2016-10-05 [18D] DEEMED TO BE WITHDRAWN

- Effective date: 20160507

2008-04-23 [17Q] FIRST EXAMINATION REPORT

- Effective date: 20080327

2004-05-26 [RBV] DESIGNATED CONTRACTING STATES (CORRECTION):

- Designated State(s): DE FR GB NL

2000-12-27 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20001027

2000-12-27 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE